The Enciclopedia del español en los Estados Unidos (2009, Santillana) is now out. It offers:
"A detailed analysis of the past, present, and future of Spanish and Hispanic culture in the U.S., highlighting the demolinguistic reality of the diverse Spanish-speaking groups living in the U.S. Attention is also drawn to the vast cultural wealth of the Hispanic community, which has driven artistic creations that today hold a preeminent position in the country's cultural landscape."
There are over 80 specialized articles covering historical, demographic, and linguistic analyses. I made contributions on codeswitching (with Carmen Silva-Corvalán) as well as an entry about mixed ethnicity Latinos. This page includes recent press about the Enciclopedia del español en los Estados Unidos.